• Journal of Animal Science and Technology
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• v.53 no.4
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• pp.333-339
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• 2011

The present study was performed to investigate the effects of pre- and post-weaning feeding programs on growth of pigs. A total of 24 litters (avg. 10.6 piglets/litter) born from multiparous (Yorkshire ${\times}$ Landrace) dams ${\times}$ Duroc sires were provided with neither creep feed (CF) nor milk replacer ("CON"), 200 gm CF/litter/d from the 15th day of lactation ("MIN"), or CF and milk replacer ad libitum for 7 h during the daytime from the 7th day ("MAX") through weaning at d 21 of age. Sixty-eight weanling pigs selected randomly from each of CON and MIN were provided with phases 1, 2 and 3 nursery diets for 7, 14, and 13 days, respectively, in two pens; an equal number of piglets from MAX received the same diets for 6, 10, and 18 days, respectively. Subsequently, all pigs were fed grower 1 and 2 diets sequentially up to d 95 and 135, respectively. The entire pre- and post-weaning feeding trial was repeated three times under a split-plot design of experiment. Initial and final weights and ADG of the suckling pigs did not differ between MAX/MIN and CON. However, final wt of MAX adjusted for initial wt, which was 0.17-kg less in MAX than in CON, was greater than that of CON by 0.31kg, whereas the difference between MIN and CON in final wt barely changed after the adjustment. Growth of the animals during the nursery and growing phases was not affected by the feeding program, whereas d 55 and 135 BW, as well as d 6 BW, were highly correlated with weaning weight (r=0.81, 0.57, and 0.76; P<0.001, <0.05, and <0.001, respectively). In conclusion, results suggest that provision of creep feed and milk replacer from early lactation may be effective for increasing weight gain of light piglets, but that limited provision of creep feed during late lactation or extension of the duration of phases 1 and 2 vs. 3 nursery diets for several days is unlikely to influence the growth of pigs during the corresponding and subsequent periods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.704-713
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• 1997

This study was conducted to describe qualitatively the protein metabolism of pigs during growth depending on the feed protein quality and to describe quantitatively amino acids requirements, using a simulation model. The used model has a non-linear structure. In the used model, the protein utilization system of a pig, which is in the non-steady-state, is described with 15 flux equations and 11 differential equations and is composed with two compartments. Protein deposition(g/day) of pigs on the 30th, 60th, 90th, and 120th day of feeding duration with three-quality protein, beginning with body weight 20kg, were calculated according to the empirical model, PAF(the product of amino acid functions) of Menke, and was used as object function for the simulation. The mean of relative difference between the simulated protein deposition and PAF calculated values, lied in a range of 8.8%. The simulated protein deposition showed different behavior according to feed protein quality. In the high-quality protein, it showed paraboloidal form with extending growth simulation up to 150eh day. So the maximum of protein deposition was acquired on the 105th day of simulate growth time and then it decreased fast. In the low-quality protein, this form of protein deposition in the course of simulated growth did not appear until 150th day. The simulated protein mass also showed a difference in accordance with feed protein quality. The difference was small on the 30th day of simulated growth, but with duration of the simulated growth it was larger. On the 150th day the simulated protein deposition of high quality protein was 1.5 times higher as compared to the low-quality protein. The simulated protein synthesis and break-down rates(g/day) in the whole body showed a parallel behavior in the course of growth, according to feed protein quality. It was found that the improvement of feed protein quality increased protein deposition in the whole body through a increase of both protein synthesis and breakdown during growth. Also protein deposition efficiency, which was calculated from simulated protein deposition and protein synthesis, showed a difference in dependence on the protein qualify of feed protein. The protein deposition efficiency was higher in pigs fed with high quality protein, especially at the simulation time 30th day. But this phenomena disappeared with growth, so on the 150th day of growth, the protein deposition of the high feed protein quality was lowest among the three different quality of feed protein. The simulated total requirement of the 10 essential amino acids for the growth of pigs was 28.1(g/100g protein), similar to NRC. The requirement of lysine was 4.2(g/100g protein).